This invention relates to an idle speed increasing apparatus for motor driven vehicles and more particularly to apparatus for increasing the idle speed of the engine of large trailer trucks when the engine must continue to run while the vehicle is stationary.
When the large multi-wheel trucks used for carrying heavy loads over long distances stop, the engine is generally kept running at idle speed, especially in hot and cold climates. The cab of such vehicles have a sleeping area so the driver, or drivers in the case of two driver trucks, can sleep in the cab when they tire while driving in a sparsely populated location, and for economical reasons, when in a location where motel rates are high. The vehicle also must stop on numerous occasions during long trips for the drivers to eat. In cold environments, when the drivers stop, the engine remains running to maintain heat within the cab, especially when they are trying to sleep, and to prevent gelling of the diesel fuel. If the engine should be shut for a short time in extremely cold weather, the diesel fuel tends to gel, thereby fouling the engine and requiring correction by a skilled mechanic. Under hot weather conditions, the engine is permitted to continue to run for driving the air conditioning unit.
One problem encountered with diesel engine driven trucks is that the idle speed is exceptionally low. Thus, even when the engine idles during such stops, the coolant temperature is such that sufficient heat in cold environments is not obtained, and the drivers find it difficult to sleep in the cab, and at exceptionally low temperatures, the fuel still tends to gel. In high temperature environments, the low idle speed results in insufficient air being drawn through the air conditioning unit so that the drivers can't sleep within the cab and are forced to stop at a motel. The low idle speed also results in the turbocharger operating at too low a speed resulting in the failure to burn all the oil out of the diesel fuel. The oil build-up weakens the oil seals causing leakage and eventual failure.
The above problems do not occur when the truck is moving and the engine is operating under normal conditions at higher engine speeds. The problem only occurs when the truck is stationary and the engine is idling or shut. For this reason some manufacturers include a throttle within the cab for increasing the engine idle speed; but other manufacturers do not provide such a speed control. The known throttle devices used in truck cabs include a cable extending through a conduit. These however, have not been dependable since corrosion of the cable or conduit have resulted in binding between the cable and conduit, conduit clogs and cable failure. More recently a simple adjustable pogo-stick pole has been tried by truck drivers for depressing the accelerator pedal, but it has been ineffective since vibration caused by the engine results in disengagement of the device from the pedal.